The Analysis of p53 and p63 Expression for the Risk Assessment of Malignant Transformation in Oral Precancerous Lesions

Oral precancerous lesions have been considered as a target tissue for the early detection and chemoprevention study. The risk of malignant transformation in oral premalignant lesions should be accurately evaluated and properly treated to prevent from cancer development. Accordingly, the risk assessment and monitoring of chemoprevention effect are critically important to reduce cancer incidence. This study aimed to evaluate the usefulness of p53 and p63 expression as biomarkers for the risk assessment to malignant transformation in leukoplakia. This study used 21 cases of oral leukoplakia without malignant transformation and 7 cases with malignant transformation during more than 2 years follow-up period which were examined at the Department of Oral Pathology, Yonsei University College of Dentistry. Six cases of normal mucosa were used as a control. Monoclonal p53 and p63 antibodies were applied for immunohistochemical study. As results, p53 expression was shown in 6 of 21 cases(29%) of the leukoplakia without malignant transformation, and in 3 of 7 cases(43%) of the leukoplakia transformed to squamous cell carcinoma. Normal oral mucosa showed no detectable p53 expression. p63 expression was detected in 9 of 21 cases(42%) of the leukoplakia without malignant transformation, and 5 of 7 cases(71%) of the leukoplakia transformed to squamous cell carcinoma. In normal mucosa 2 of 6 cases(33%) showed p63 expression in basal and parabasal layer. These results suggest that p53 and p63 expression requires more intensive further study based on the longer period of follow-up and the larger scale-examination for the verification of the usefulness as a predictable biomarker assessing the risk of malignant transformation in oral precancerous lesions.ope